DE102007059933B3 - Device for braking and clutching with non-contact power transmission - Google Patents

Abstract

The present invention relates to an apparatus for braking and coupling with non-contact power transmission, comprising a rotary drum (100) and a holding drum (200). The rotary drum is mounted on a rotary drum shaft (105). The holding drum is provided with driver elements and longitudinally displaceable on a holding drum shaft (205). The rotary drum is provided with rotary drum inner rings (103) and the holding drum with holding drum inner rings (203), which are each provided on both sides with diametrically magnetized bar magnet (10), which after insertion of the holding drum in the rotary drum in the direction of the first arrow (1), separated by air gaps (215), are polar opposing and exert attractive forces on each other. Thereby it is e.g. possible to control an impeller (30) of a motor vehicle connected to the rotary drum and decelerate it without contact.

Description

The The present invention relates to a device for braking and clutching, in which for braking, or coupling two rotatable or longitudinally movable Elements required forces contactless transmitted by permanent magnets become.

The The proposed invention is also particularly suitable for use in Vehicles, especially in motor vehicles usual brakes and clutches replace, where the power transmission through Friction takes place, making a constant Abrasion wear connected is replaced and the respective wear parts at certain intervals Need to become. In one embodiment radially magnetized permanent magnets each on a holding drum and attached to a rotary drum, wherein the holding drum axially is displaceable and the magnets exert attractive effect aufeinender.

The The present invention can also be applied to braking and Clutches of carriages which are guided mechanically on rails. These facilities are considered as transport systems for workpieces of one to the next Processing level used and are as linear systems in the industrial Known mass production.

contactless power transmission between rotatable and longitudinal movable elements are known by diverse design of the power transmission by electromagnets. However, these known arrangements are constructive very expensive and need a controlled power supply, with a secured end position the elements to be braked are not always guaranteed.

The usual, In vehicles built-in brakes and clutches need to their activity directly or indirectly exercised forces because the brake and / or the coupling process by frictional engagement he follows. The same is true for Aircraft landing gear brakes.

The present invention includes but also other applications in which a non-contact power transmission between one longitudinal moving movement element, z. B. in the form of a carriage, the on guided a rail is done, taking the measure of About force meeting between the moving element and the holding element only by change reaches the distance between the moving element and retaining element becomes.

at a known rotary friction brake, z. B. a disc brake, would be analogous to the brake disc the moving element and the brake shoes the holding element.

devices for braking, or coupling, a rotary rotary drum and a along this Have adjustable holding drum and with magnets for power transmission are provided, are known.

The US 2,437,871 shows a magnetic coupling with a hollow cylinder ( 1 ), on a first wave ( 2 ) and the longitudinally magnetized permanent magnet ( 17 ) is provided. In this hollow cylinder is a, smaller diameter cylinder ( 3 ) insertable on a second shaft ( 5 ) longitudinally displaceable, but rotatably connected to this, is attached. The small cylinder ( 3 ) is also with longitudinally magnetized magnet ( 18 ) whose polarity is the same as that of the magnets ( 17 ). For power transmission of the smaller cylinder in the larger cylinder by means of a hand lever ( 12 ) inserted. As a result of the arrangement of the magnets and their Pollarisierung basically only small forces can be transmitted. The mentioned document is not apparent, for which purpose this known device should be used.

The DE 37 32 766 A1 describes a permanent-magnet excited hysteresis clutch or brake which has a hysteresis part (FIG. 1 ) and one of an inner and an outer pole ring ( 3 . 4 ) existing exciter part ( 2 ), wherein the magnetic poles are arranged on both lateral surfaces of the bell rotor. The pole rings ( 3 . 4 ) consist of soft magnetic material and permanent magnet pieces ( 5 . 6 ), which are completely embedded in the soft magnetic material, so that the bell rotor facing magnetic poles are formed alternately of permanent magnet and soft magnet. The inner and the outer pole ring ( 3 . 4 ) are rigidly interconnected, but magnetically by a non-magnetizable intermediate ring ( 7 ) separated. A controlled torque can be achieved by a variable immersion depth of the hysteresis ring body ( 2 ) be achieved. The pole rings are formed so that the same from the outer to the inner pole ring each poles radially opposite. This known device is based on the hysteresis principle in which energy is converted into heat by magnetic reversal and in this case a force effect between the relatively moving parts is achieved. However, this force is so low that it is not sufficient to achieve higher torques, as z. B. are required in motor vehicles. This mentioned document is not apparent, for which purpose this known device is to be used.

The DE 197 36 797 A1 describes a regulated drive for a motor vehicle ventilator, the like is formed in that one, controlled by the engine of the motor vehicle driven magnetic coupling with variable slip the fan ( 1 ) drives. On a carrier disk ( 21 ) are permanent magnets ( 7 ) arranged radially, which are poled axially, wherein adjacent magnets have a reverse polarity. When the carrier disk is rotated, forces are transmitted to a driver part as a result of the hysteresis ( 10 ), whereby the carrier part, on which a fan wheel ( 1 ) and which consists of a hysteresis material, is driven with slip. The control of the driving force takes place by axial displacement of the carrier part to the driver part. This known device can transmit only small torques, although to drive a fan wheel, but not for braking, or coupling in motor vehicles u. Ä. sufficient.

The DE 197 05 290 A1 describes a hysteresis brake which, with a roller ( 9 ) non-rotatably connected hysteresis ring ( 1 ) and provided with magnetic poles magnetic ring. The magnetic ring ( 2 ) of permanent magnet material is arranged within the hysteresis ring, wherein the magnetic poles along the outer circumference of the magnetic ring ( 2 ) are impressed alternately. The magnetic ring surrounds a carrier part ( 4 ), the rotation secured, but via an adjusting device ( 7 ) axially displaceable on the axis ( 5 ) is stored. This known brake serves as a drain brake in the processing of material in a production plant such. Stranding, spooling, spooling, etc. The equipment defines the rate at which the material is withdrawn from the drain, with the drainage brake defining the tensile force. As a result of the hysteresis principle, this known brake can not transmit forces which are required for braking and clutching motor vehicles, etc.

The JP 2001 099 194 A describes an electromagnetic clutch, which starts from the task, the torque acting on a holding element ( 6 ) is maintained to hold constant when this holding element is adjusted by longitudinal forces. To avoid this adjustment, an inner ring magnet ( 5 ) and on a hollow cylinder ( 2 ) an outer ring magnet ( 3 ), whose magnetic force is greater than that of the inner magnetic ring. The object of this known device emanates and their solution by means of electromagnets, does not correspond to the task from which the present invention proceeds. The present invention does not include electromagnets.

The DE 948 794 describes an electromagnetic brake in which between two mutually rotatable drums or discs, one of which is energized by the braking current as an electromagnet, the braking force is generated by magnetic action. This known brake uses electromagnets which are not part of the present invention and whose use is superfluous by the present invention.

The GB 282,876 describes a vehicle brake, in which on the outer circumference of a retaining disc (c) in pairs electromagnets (e) are mounted, between each of which a ring (a) is connected from magnetizable the corresponding wheel of the vehicle. By energizing the electromagnets, the braking force is generated. This known brake uses electromagnets whose use is superfluous by the present invention.

• 1. Die Betätigung des Brems, bzw. Kupplungsvorganges soll nur geringe für das Bremsen. bzw. das Kuppeln selbst nicht erforderliche, sehr kleine Verstellkräfte erfordern,
• 2. die zu bremsenden, bzw. zu kuppelnden Flächen sollen sich nicht berühren,
• 3. beim Einsatz als Bremse soll der Bremsvorgang bezüglich der Bremswirkung lediglich durch Betätigung des Verstellorgans, bei Kraftfahrzeugen z. B. der Fußbremse, ohne besonderen Kraftaufwand, stufenlos durchführbar sein, bis zum Bremszustand über die „Stotter-Bremse", wodurch das als ABS-System bekannte System, dass die herkömmlichen Reib-Bremsen ansteuert, überflüssig wird,
• 4. die Vorrichtung soll konstruktiv einfach und volumenmäßig klein gestaltungsfähig sein,
• 5. ein Austausch von Brems- und Kupplungs-Elementen soll überflüssig sein,
• 6. es soll kein mechanisches Nachstellen der Elemente der Vorrichtungs-Elemente erforderlich sein,
• 7. die erfindungsgemäße Vorrichtung soll sowohl vorhandene Brems-, als auch Kupplungssysteme ohne besonderen konstruktiven Aufwand ersetzen können,
• 8. die Vorrichtung soll vollkommen kapselbar sein zur Vermeidung des Eindringens von Staub und Flüssigkeit,
• 9. die Vorrichtung soll wege-, geschwindigkeits- und beschleunigungsabhängig mittels bekannter Sensoren, mit Hilfe einer Programmiereinrichtung, durch einen einfachen, wenig Kraft erforderlichen Hubmechanismus bezüglich ihres Verstellweges und damit ihrer Bremswirkung ansteuerbar sein und
• 10. die Vorrichtung soll auch bei gerade oder kurvig ausgebildeten Linearsystemen, die mit Transportschlitten versehenen sind, in oben genannter, entsprechender Weise verwendbar sein.

The present invention is therefore based on the following task:

• 1. The operation of the brake, or coupling process should be low for braking. or the coupling itself does not require necessary, very small adjustment forces,
• 2. the surfaces to be braked or to be coupled should not touch each other,
• 3. when used as a brake, the braking process with respect to the braking effect only by pressing the adjustment, in motor vehicles z. As the foot brake, without special effort, be continuously feasible until the braking state on the "stutter brake", whereby the system known as ABS system that controls the conventional friction brakes, is superfluous,
• 4. The device should be structurally simple and volume small designable,
• 5. An exchange of brake and clutch elements should be superfluous
• 6. no mechanical readjustment of the elements of the device elements should be required
• 7. the device according to the invention should be able to replace existing brake systems as well as clutch systems without any special design effort,
• 8. The device should be completely capsuled to prevent the ingress of dust and liquid,
• 9. The device should we-, speed and acceleration depending on known sensors, with the help of a programmer, by a simple, little force required lifting mechanism with respect to their adjustment and thus their braking effect be controlled and
• 10. The device should also be used in straight or curved linear systems, which are provided with transport carriages, mentioned above, corresponding manner.

This object is achieved by a device for braking and clutching with non-contact Power transmission solved according to the description, the drawings and the claims.

in the Principle is the solution the task is that a non-contact Power transmission between a rotatable, or longitudinal out Movement element and a holding element by permanent magnets, preferably rod-shaped are formed and magnetically diametrically polarized on the respective movement element and attached to the respective holding element are, and polarized in opposite directions, through an air gap separated, opposite stand. The power transmission takes place during relative movement of the movement element to the holding element through impulsive attractions the individual magnets, with a continuous reduction of the relative movement up to the full Braking possible is by moving the holding element relative to the moving element, whereby the instantaneous number of opposing magnets up to their maximum number changeable is. In the context of the invention it is also possible, individually or twice arranged leaflike, normal Magnetized permanent magnets as pot magnets instead of the diametrically magnetically tested magnets use. The holding element here is always, although with respect to the moving element longitudinally movable, however, as to the force, or torque transmission stationary appropriate.

The The invention will be explained with reference to drawings. It shows:

1 a schematic view of the device according to the invention in the embodiment as a brake of an impeller of a motor vehicle, wherein the rotatable movement element is connected as a rotary drum by means of a known suspension with the shaft of the impeller and the holding element is in the form of a displaceable holding drum whose outer diameter is smaller than that Outer diameter of the rotary drum, wherein the rotary drum is not in braking engagement with the holding drum,

2 a representation according to 1 in the functional position in which the holding drum is fully inserted in the rotary drum in the sense of full braking,

3 a schematic view of the device according to the invention, mutatis mutandis 2 but in an embodiment in which the outer diameter of the holding drum is larger than the outer diameter of the rotating drum,

4a a half-longitudinal section of the upper portion of 3 in the functional position without braking effect,

4b a half-longitudinal section of the lower portion of 3 in the functional position with braking intervention,

5a a half-longitudinal section of the upper portion of the upper portion of an arrangement of the device according to the invention, in which an additional holding drum is provided and in the unbraked functional position,

5b a half-longitudinal section of the lower portion of the illustration according to 5a In the braking functional position,

6 a section II according to 3 in which individual bar magnets are drawn in to indicate the complete equipping of a rotary drum and a holding drum with these bar magnets,

7 a detail A according to 6 .

8th a section II-II according to 7 .

9 a perspective, schematic representation of an embodiment of the invention, in which the rotary drum and the holding drum are provided with normal magnetized, preferably cylindrical, referred to as pot magnets permanent magnets,

10 a view III according to 9 , a view III according to 9 .

11 a view III according to 9 , a view III according to 9 in one embodiment with paired pot magnets arranged one behind the other,

12 a partial top view of a rotary drum inner ring, or a holding drum inner ring with parallel to each other and arranged parallel to the rotational axis of the rotary drum, diametrically magnetized bar magnet,

13 a partial top view according to 12 with diametrically magnetized bar magnets parallel to one another but inclined to the axis of rotation of the rotary drum,

14 FIG. 2 is a partial plan view of a slide carried on a rail and provided with an electromagnet operatively connected to a brake plate. FIG.

15 a section IV-IV according to 14 in braking position and

16 a section IV-IV according to 14 in unbraked functional position,

17 a detail "B" according to 6 with external conformations of the rod magnets to the device with respect to a reduction of the air gap,

18 a side view of 1 . 2 and 3 , wherein the rotary drum is provided with cooling fins and

19 a view VV according to 18 ,

The device according to the invention, independently rotational or longitudinal motion is basically based on that a longitudinally movable Holding element, which is provided with permanent magnets, another moving element that rotates or moves in the longitudinal direction and also is provided with permanent magnets whose movement, depending on the purpose, stepless, graduated or, with the inclusion of the aforementioned Application purposes, decelerates quickly, or put in hibernation.

One of the many possible applications of the present invention is in 1 designed as a wheel brake and shown in its initial position. An impeller 30 on a roadway 31 is rolling on a standard wheel suspension 110 a motor vehicle mounted. A rotary drum 100 is with a hollow rotary drum shaft 105 rotatably by means of a rotary drum plate 101 and a fastener 106 connected. Out 4a it can be seen that the rotary drum shaft 105 on a guide shaft 250 is stored. On the other end of the guide shaft 250 is a holding drum shaft 205 stored. The leadership wave 250 can consist entirely of a suitable bearing metal. However, it is also possible that one end of the guide shaft fixed to the rotary drum shaft 105 to connect and the other end of the guide shaft 250 to be stored by means of a not shown bearing.

The hollow holding drum shaft 205 is outside with driver elements 206 provided in the form of feather keys or formed as a wedge or in total as a polygon shaft.

The rear end of the drum holder shaft 205 is on the vehicle frame 350 attached.

On these driver elements 206 is a sliding element 208 , in engagement with this, longitudinally displaceable. On the sliding element 208 is by means of a holding drum plate 201 a holding drum 200. attached.

The axis of rotation of the rotary drum 100 is identical to the general axis of rotation 40 ,

The rotary drum 100 has a rotary drum outer ring 102 and a plurality of concentric rotary drum inner rings 103 on. Between the rotary drum inner rings 103 are each rotary drum recesses 104 provided in the holding drum inner rings 203 can be inserted, which is attached to the holding drum plate 201 , are also concentric.

On the inner and outer surfaces of the rotary drum inner rings 103 and the retaining drum inner rings 203 are in the preferred embodiment bar magnets 10 mounted one behind the other, which are diametrically permanently magnetized lengthwise. The bar magnets 10 are respectively at the outer and inner circumferences of the rotary drum inner rings 103 , or the holding drum inner rings mounted in such a way that in each case a south-magnetized side 10.1 a north-magnetized side 10.2 stand opposite. This is in 7 and 8th shown.

The various possible arrangements of bar magnets 10 is out 6 seen. When the holding drum inner rings 203 according to 6 . 4b and 5b in the rotary drum recesses 104 are inserted for the purpose of braking the rotational movement of the rotary drum, each is an air gap 215 present, which is the direct contact of the opposing bar magnets 10 prevented and its thickness is about 0.2 to 1.0 millimeters, depending on the purpose and the manufacturing accuracy. As is known, the smaller the distance between the two magnets, the greater is the force of attraction between two magnets magnetized in opposite directions.

The bar magnets 10 are commercially available and can also according to 17 be made in a geometric shape, which increases the force between two, opposing bar magnet. The material in which the bar magnets 10 are attached, is not magnetizable. As such, z. As aluminum, copper, plastic o. Ä. Suitable. The attachment of the bar magnets 10 is possible in various ways known to those skilled in the art. So z. B. the holes for the bar magnets are produced on automatic machine tools. It is Z. B. also possible to make the holes mentioned so that they are incorporated into the holding drum, or in the rotary drum when they are made as chill casting in a metal mold. The bar magnets 10 be used by hand or by machine in the holes mentioned, the bar magnets are surrounded with a known, thermally conductive paste, the, due to the power transmission between the individual bar magnet 10 resulting heat transfers to the holding drum, or to the rotary drum.

To improve the cooling are according to 18 and 19 cooling fins 107 on the outside of the rotary drum plate 101 intended. Depending on the embodiment of the device, other known cooling elements can be used.

On the sliding element 208 is an actuator 297 attached to which a non-drawn element in the direction of the first arrow 1 ( 1 ) and thus the holding drum 200. in the rotary drum 100 inserts. The mentioned, not shown element may be a lever in connection with a brake pedal or a lever whose operation is controlled by an electronic, pneumatic or hydraulic device. In 4b you can see how the holding drum 200. completely in the rotary drum 100 retracted and thereby causes their stoppage.

During the retraction of the holding drum in the rotary drum force pulses between the bar magnet of the rotary drum and the holding drum are effective, which reduce the rotational movement of the rotary drum. The energy is destroyed by the bar magnet 10 transferred to the rotary drum and the holding drum, wherein the holding drum can also be provided with not shown cooling fins.

at braking in motor vehicles it is known that a full braking blocked with wheels must be avoided. For this purpose, based on the foot-operated "stutter brake" an electronic developed controlled system that controls the brake elements so that prevents impeller lock and that is known as ABS system.

The present invention, by simple design, makes the ABS system redundant. It is namely in the context of the invention, the bar magnets 10 to be arranged so that at the beginning of the insertion of the holding drum in the rotary drum, the braking operation begins slowly, which is due to the arrangement of the bar magnets 10 is possible and upon further retraction of the holding drum, the bar magnets 10 according to the detail B in 6 due to their sectioned arrangement prevent the blocking effect.

When braking, ie when retracting the holding drum in the rotary drum and a very gentle initial braking can be achieved in that 12 Rows of bar magnets 10 z. B. parallel on a rotary drum outer ring 102 are arranged, while on the, this facing surface of the respective rotary drum inner ring, rows of oblique to the axis of rotation 40 arranged bar magnet according to 13 are attached.

There are in the context of the invention, based on brakes, also further braking effects possible. So is according to 4a and 4b the inside of the narrower barrel drum outer ring 202 with parallel to each other and parallel to the axis of rotation 40 aligned bar magnet while on the surface of the rotary drum outer ring arranged underneath 102 also parallel bar magnets according to the principle of the detail B according to 6 are attached.

It is an essential feature of the present invention that no force is needed for the braking process itself. Overcoming the force of a compression spring 220 ( 4a . 4b and 5b ) to retract the holding drum is very low. To extend the holding drum from the rotary drum only needs the compression spring 220 be relieved. In this way it is possible, in connection with the mentioned arrangement possibilities of the bar magnets 10 to produce a stepless braking effect. To solve the braking effect is only the compression spring 220 relieved. The retraction and extension of the holding cylinder in the rotary cylinder is infinitely and without direct application of force for the braking itself.

Another, within the scope of the invention, embodiment of the invention as a brake is in 5a , respectively. 5b shown. This is in addition to the shift element 208 an additional displacement element 209 arranged, which also with driver elements 206 is provided. At the additional displacement element 209 is an additional holding drum 300 with an additional outer ring 301 by means of a holding drum plate 201 mounted longitudinally displaceable. The inside of the additional outer ring 301 and the outside of the rotary drum outer ring 102 are each with parallel bar magnet 10 provided accordingly 12 , Between the additional sliding element 209 and the holding drum plate 201 is an additional compression spring 221 provided, the spring constant greater than that of the compression spring 220 ,

Will now the additional holding drum 300 in the direction of the first arrow 1 moved, because of the lower spring constant of the compression spring 220 first the holding drum 200. in the rotary drum 100 inserted. When increasing the force on the additional compression spring 221 is also the additional outer ring 301 over the rotary drum outer ring 102 pushed, thereby enabling full braking, or is facilitated.

In the present invention, it is also possible, using the above description, the rotary drum 100 and the holding drum 200. to use as a clutch, by only the rear part of the drum holder shaft 205 Not is held, but with a rotatably mounted element, for. B. can be connected to a clutch disc. As a result, it is also possible to produce fixed and slipping clutch systems, since the torque transmission between the rotary drum 100 and the holding drum 200. is variable.

In the context of the invention, it is also possible within a transfer system according to 14 . 15 and 16 a sled 500 as a moving element and as a holding element a rail 400 use. The sled 500 is with any transport element 503 provided, z. B. for transporting workpieces. The sled is on a rail 400 guided and moved by not shown facilities. The present invention now provides on the carriage 500 a magnetic strip 401 and on the rail 400 an electromagnet 501 to attach, the rod with a brake bar 502 is provided. The magnetic strip 401 and the brake bar are each with bar magnets 10 Mistake. When the sled 500 in the direction of the third arrow ( 14 ) and a position according to 16 reached. Moves the brake bar 502 controlled in the direction of the fourth arrow 4 down and slows down the movement of the slide.

For transmitting lower torques, it is also within the scope of the invention, the inner surface of the holding drum 200. , the outer surfaces of the rotary drum 100 , as well as the inner rings of the holding drum and the rotary drum with cylindrical pot magnet 20 to be provided individually according to 9 and 10 or twice according to 11 are arranged. These pot magnets are conventionally NS magnetized.

• a) Der Austausch von Verschleißteilen, bezogen auf die Drehtrommel 100 und die Haltetrommel 200 ist nicht erforderlich,
• b) eine mechanische Nachstellung der Elemente der Erfindung ist nicht nötig,
• c) die erfindungsgemäße Vorrichtung ist insgesamt gegen Umwelteinflüsse- kapselbar,
• d) die erfindungsgemäße Vorrichtung ist nachrüstbar, bzw. austauschbar gegen bestehende Systeme,
• e) die Bedienung der Vorrichtung kann automatisiert werden, so dass eine Betätigungseinrichtung, die das Ein- und Ausfahren der Haltetrommel in die Drehtrommel bewirkt, programmierbar ist, wobei eine Notbremsung bei Ausfall der Automatik stattfindet,
• f) die Vorrichtung kann auch als Rutschkupplung verwendet werden, wobei die Kraftwirkung durch bekannte Sensoren verschiedener Wirkungsweisen einstellbar ist und
• g) die Vorrichtung hat insgesamt ein geringes Gewicht.

When using the present invention, further advantages result:

• a) The replacement of wearing parts, based on the rotary drum 100 and the holding drum 200. not necessary,
• b) a mechanical adjustment of the elements of the invention is not necessary
• c) the device according to the invention can be encapsulated in total against environmental influences,
• d) the device according to the invention can be retrofitted or exchanged for existing systems,
• e) the operation of the device can be automated, so that an actuator that causes the retraction and extension of the holding drum in the rotary drum is programmable, with an emergency braking takes place in case of failure of the automatic,
• f) the device can also be used as a slip clutch, the force being adjustable by known sensors of different modes of action and
• g) the device has a low overall weight.

100

rotary drum

101

Rotary drum plate

102

Rotary drum outer ring

103

Rotary drum inner rings

104

Rotating drum recesses

105

Rotary drum shaft

106

fastener

107

cooling fins

110

Wheel suspension

200

holding drum

201

Holding drum plate

202

Holding drum outer ring

203

Holding drum inner rings

204

Holding drum recesses

205

Holding drum shaft

206

dogging

207

actuator

208

displacement element

209

Additional sliding shaft

215

air gaps

220

compression spring

221

Additional pressure spring

250

guide shaft

300

Additional holding drum

301

Additional outer ring

350

vehicle frame

400

rail

401

magnetic strip

500

carriage

501

electromagnet

502

brake bar

503

transport element

10

bar magnets (diametrically magnetized)

10.1

South magnetized page

10.2

North magnetized page

20

pot magnets

30

Wheel

31

roadway

40

axis of rotation

1

first arrow

2

second arrow

3

third arrow

4

fourth arrow

Claims (5)

An apparatus for braking and coupling with non-contact power transmission, comprising a rotary drum and a holding drum, wherein the holding drum with a holding drum outer ring and arranged concentrically to this, with holding drum inner rings and the rotary drum with a rotary drum outer ring and concentrically arranged therewith, with rotary drum Inner rings is provided and on the respective outer and inner rings au ßen and inside permanent magnets are mounted, and the rotary drum to the holding drum is axially displaceable, characterized by the following features: 1.1 on a hollow rotary drum shaft ( 105 ) which is rotatable about an axis of rotation ( 40 ), on a guide shaft ( 250 ) is, by means of a rotary drum plate ( 101 ) and a fastener ( 106 ) a rotary drum ( 100 ), 1.2 the rotary drum ( 100 ) is provided with a rotary drum outer ring ( 102 ) and a plurality of concentrically arranged rotary drum inner rings ( 103 ), between each of which rotary drum recesses ( 104 ) 1.3, on the rear end of the guide shaft ( 250 ) is a hollow holding drum shaft ( 205 ), the outside with driver elements ( 206 ) is provided in the form of feather keys or which is designed as a wedge or as a polygon shaft, 1.4 on the holding drum shaft ( 205 ) is a displacement element ( 208 ), on which by means of a holding drum plate ( 201 ) a holding drum ( 200. ), which is provided with a plurality of concentrically arranged holding drum inner rings ( 203 ), between each of which holding drum recesses ( 204 1.5, the underside of the retaining drum outer ring ( 202 ), the top of the rotary drum outer ring ( 102 ), as well as the upper and lower sides of the rotary drum inner rings ( 103 ) and the holding drum inner rings ( 203 ) are in rows with bar magnets ( 10 ), which are magnetized permanently diametrically, wherein the series arrangement of the bar magnets ( 10 ) parallel or obliquely to the longitudinal axis ( 49 ) is possible, 1.6 the holding drum ( 200. ) is by means of, on the displacement element ( 208 ) attached sliding element ( 208 ) in the direction of the first arrow ( 1 ) in the rotary drum ( 100 ), in which, in this functional position, each rotary drum inner ring ( 103 ) between two two holding drum outer rings ( 202 ), 1.7 the outward magnetization poles z. B. South magnetic side ( 10.1 ), or north magnetic side ( 10.2 ) of the bar magnets ( 10 ) located on the respective surface of a rotary drum outer ring ( 102 ) and that of a holding drum inner ring ( 203 ), are magnetically oppositely poled, 1.8 in the functional position in which the holding drum ( 200. ) in the rotary drum ( 100 ) is retracted, is a respective air gap ( 215 ) with a thickness of about 0.3 to 1.0 millimeters between the rotary drum inner rings and the holding drum inner rings, 1.9 between the displacement element ( 208 ) the rotary drum plate ( 101 ) is a compression spring ( 220 ) and 1.10 the rear end of the holding drum shaft ( 205 ) is either fixable or 'freely rotatable. Apparatus according to claim 1, characterized in that the rotary drum shaft ( 105 ) via a conventional impeller suspension ( 110 ) with an impeller ( 30 ) is connected to a motor vehicle, wherein the actuating element ( 207 ) functionally with a mechanical element, for. B. a foot pedal or with an electronically controlled actuator is adjustable. Apparatus according to claim 1, characterized in that on the displacement element ( 208 ) an additional shift shaft ( 209 ) is mounted on an additional holding drum ( 300 ) with an additional outer ring ( 301 ), wherein an additional compression spring ( 221 ) between the additional shift shaft ( 209 ) and the holding drum plate ( 201 ) is provided, wherein the spring constant of this additional compression spring is greater than that of the compression spring ( 220 ). Apparatus according to claim 1, characterized in that the rotary drum inner outer sides, as well as the holding drum single or double with pot magnets ( 20 ), which are magnetized normally and in each case oppositely polarized on the surfaces of the rotary drum inner rings ( 103 ), or the holding drum inner rings ( 203 ) are mounted. Apparatus according to claim 1, characterized in that on a carriage ( 500 ), in a rail ( 400 ) in the direction of a third arrow ( 3 ), one with bar magnets ( 10 ) provided magnetic strip ( 401 ) fitted with a braking bar ( 502 ), also with bar magnets ( 10 ), cooperates with the brake bar ( 502 ), the z. B. on an electromagnet ( 501 ), in the direction of the fourth arrow ( 4 ) is moved downwards.